Small cluster of serpiginous flow voids is seen in the right superior frontal gyrus. Limited MRA confirms a nidus of tortuous vessels derived from an incompletely imaged arterial feeder (which on CTA was seen to arise from the right anterior cerebral artery). There is a minimal surrounding FLAIR hyperintensity consistent with gliosis but no evidence of haemorrhage. No mass effect is demonstrated.
There are multiple (three) punctate foci of diffusion restriction in the cortex of the left superior frontal lobe, left occipital lobe and left parietal lobe. Old left thalamic lacunar infarct. No other signal abnormality identified. Mega cisterna magna is incidentally noted.
Conclusion: Right frontal arteriovenous malformation with no evidence of haemorrhage. Given the co-existence of a pulmonary arteriovenous malformation, hereditary haemorrhagic telangiectasia is the likely underlying aetiology as previously stated.
Three punctate foci of diffusion restriction in the left cerebral hemisphere are consistent with acute ischaemia. These are most likely embolic, with the pulmonary arteriovenous malformation a possible cause of paradoxical embolism.